Pressurization apparatus

ABSTRACT

Disclosed is apparatus for enclosing, sealing and pressurizing small containers such as tennis ball cans. The apparatus includes a collar removeably affixed to the can and adapted to mate with a cap and pump assembly which seals the top of the can and injects air into the can to achieve and maintain the desired pressurized environment in the can.

United States Patent 1191 Helms Dec. 10, 1974 15 PRESSURIZATION APPARATUS 3,415,351 12/1968 Van Natter ..206/46 B 3,581,881 6/1971 Hobbs 206/46 B X [751 Helms Dallas 3,672,114 6/1972 Sacks 53/88 [73] Assignee: -Matchpointlndustrles,]1nc., Dallas,

T Primary ExaminerTravis S. McGehee Filed: J 1973 Attorney, Agent, or Firm-Jack A. Kanz [21] Appl. No.: 372,332 [57] ABSTRACT Disclosed is apparatus for enclosing, sealing and pres- 52 US. Cl. 206/315, 53/88 surizing small containers such as tennis ball an The 51 1m. (:1. B6581 85/16 apparatus includes a collar removeably affixed to the [58] Field of Search 53/88; 206/46 B can and adapted to mate with a p and p p assembly which seals the top of the can and injects air into [56] Refe ence Ci d the can to achieve and maintain the desired pressur- P iZCd environment in the can.

1,079,450 11/1913 Staunton 53/88 8 Claims, 2 Drawing Figures PATENTEL 553 I 01974 PRESSURIZATION APPARATUS This invention relates to apparatus for pressurizing small containers. More particularly it relates to simple, inexpensive means for pressurizing or repressurizing small containers such as tennis ball cans or the like.

Many items are preferably storedin pressurized or slightly pressurized containers. For example, ordinary tennis balls are manufactured in a sealed condition containing internal air pressure of about 8 psi. However, tennis balls are made from natural rubber, and natural rubber has a very high diffusion coefficient. Accordingly, the pressurization'of the tennis balls begins decreasing as soon as the ball is manufactured unless I the ball is kept in a pressurized environment. Furthermore, since the ball is made of natural rubber, a difference in internal and external pressure will also cause the ball to expand. Therefore, it is well known that tennis balls slowly lose their resiliency through expansion and loss of air.

To maintain tennis balls in the manufactured condition until use they are packaged, usually three to a container, in a pressurized container. The containers are generally pressurized so that the air pressure on the outside of the ball is approximately equal to that inside the ball. Accordingly, the ball remains in its original manufactured state until the container is opened. However, upon opening the container the container pressure is lost. Unless the ball is replaced in a pressurized environment, it will begin losing its pressurization and begin expanding slightly. Ordinarily tennis balls will gradually lose pressurization and will become unacceptable for use within 7 to days at atmospheric conditions. Such insufficiently pressurized or expanded balls are generally referred to as ,dead" balls.

In accordance with the present invention pressurization apparatus is provided which may be advanta-- geously attached to conventional tennis ball cans or other suitable containers. The apparatus comprises a collar means for interconnection with the conventional container to which a combined lid and pump is attached. The tennis balls are replaced in the original container, the collar placed on the container and the lid and pump combination attached to the collar. The pump may then be activated to repressurize the container to about 8 psi, thereby maintaining the environment surrounding the tennis balls in the container at approximately the same as the pressure inside the tennis ball and preventing any further loss of pressurization. Furthermore, since the container is repressurized to the desired internal pressure, replacing the slightly depressurized or dead" balls in a pressurized container will, to some extent, repressurizethe balls.

The apparatus of the invention is extremely simple in mechanical design and requires no modification of conventional tennis ball cans. Therefore the device may be inexpensively manufactured and used as a replacement lid on a conventional tennis ball can. The user may simply replace the balls in the original container, attach the apparatus of the invention to the container, repressurize the container and leave the pump and lid combination on the can until the balls are removed for further use. Thereby the useful life of tennis balls may be vastly increased. Other features and advantages of the invention will become more readily understood when taken in connection with the appended claims and attached drawings in which:

FIG. 1 is a sectional view of the preferred embodiment of apparatus of the invention attached to a conventional tennis ball can, and

FIG. 2 is an exploded view of the pump, lid and collar assembly shown in FIG. 1.

Referring now to FIG. I there is illustrated a conventional tennis ball container 10 with the apparatus of the invention attached thereto. Conventional tennis ball cans are hermetically sealed to provide a sealed container for shipment and storage of the balls before use. Conventional cans are cylindrical having a metal tearaway or other conventional opening at the top end. Accordingly, when the can is opened the entire lid is removed to allow removal of the balls from the can.

Conventional cans generally include a groove 11 near the open end. The groove is immediately adjacent the bead 12 formed by the top of the can when the conventional top is placed on the can. The bead extends radially from the periphery of the top of the can forming a small flange. When the can is opened the flange or bead 12 remains on the top of the can adjacent the groove 11 forming a lip at the open end of the can.

In accordance with the preferred embodiment of the invention the groove 11 and bead 12 are utilized to attach the resealing and pressurization mechanism described hereinafter.

As illustrated in FIG. 2 the invention comprises a collar 20 having internal dimensions which are less than the external dimensions of the bead 12 but greater than or sustantially equal to the external dimension of the can at the groove 11. Preferably the collar 20 is somewhat flexible or pliable so that it may be attached to the can by placing it in the groove 11 and stretching the collar to slide over the bead 12. The collar then rides loosely in groove 11. The groove, therefore, provides a convenient means for allowing installation of the collar.

An elastic retainer 21 is used to firmly secure collar 20 adjacent bead 12. The retainer 21 may be a simple O-righ, a large rubber band or the like. The retainer 21 is placed on the can and moved below the groove 11 before the collar 20 is placed thereon. The retainer 21 is then rolled up the can and into the groove 11. As the retainer 21 contracts within groove 11 it will contact the lower edge of collar 20 and urge the collar 20 upwardly to position snugly against the bead 12 or the top side of the. groove 11 as illustrated in FIG. 1. The retainer 21 thus acts to immobilize the collar and hold it firmly in place for attachment of the lid and pump assembly.

Collar 20 is preferably fabricated from a semi-rigid material such as plastic or nylon and includes a plurality of outwardly or downwardly depending lugs 22. The bottom surfaces of lugs 22 are inclined with respect to the plane of the collar to serve as an attachment and compression thread for the lid. as will be explained hereinafter.

As shown in FIGS. 1 and 2 a disc 23 is fitted over the open end of the can 10. The disc 23 has a diameter substantially equal to the external diameter of head 12. An elastic sealing material 24, such as rubber, is attached to the underside of disc 23 at the outer periphery thereof and is adapted to mate with the top surface of the bead 12. When the disc 23 and seal 24 are held firmly against the bead 12, the can 10 is hermetically sealed. As shown in the drawings, disc 23 is held in place by cap 25.

In the preferred embodiment the cap includes an upwardly projecting cylindrical barrel 28. A piston 29 is slideably mounted for reciprocal movement in the barrel 28. A handle or knob 30 is mounted on top of the piston and acts as a stop to limit downward travel of the piston 29 within the barrel 28. A sealing cup 31 is attached to the lower end of the piston to provide moveable sealing contact between the interior of the barrel and the piston 29. The sealing cup 31 may be a simple flexible cup-shaped member attached to the lower end of the piston by conventional means such as a screw 32 or the like. It will thus be observed that disc 23, barrel 28 and piston 29 define an enclosed variable volume chamber 33.

The disc 23 includes a check valve 34 permitting air flow from the chamber 33 into the interior of can 10 but preventing air flow in the opposite direction.

In the embodiment illustrated, internal can pressure of only approximately 8 psi need be attained. Therefore a very simple check valve may be utilized. For example, in the illustration ofFlG. 2 the check valve may be a thin sheet of flexible material such as neoprene rubber having one edge attached to the underside of the disc -23 and overlying a hole 35 in the disc. Therefore air entering the can through hole 35 will move the flap 34 downward but air pressure within the can will close the flap against the hole and block the escape of air from the can when the pressure within the chamber 33 is less than the pressure within the can 10. Other simple check valve arrangements will be apparent to those skilled in the art.

It will be observed that with the collar 20, retainer 21, sealing disc 23 and cap 25 in place, the interior of the container 10 may be pressurized by simply pumping the piston 29. During upward travel of the piston 29 air leaks around the sealing cup 31 into the chamber 33. As the piston is pushed downward sealing cup 31 expands to sealingly engage the walls of barrel 28 and compress the air within chamber 23 by reducing the volume within the chamber 33. As the air pressure is increased in chamber 33 check valve 34 opens to permit air to flow from chamber 33 into the interior of the can. Repeated strokes with piston 29 will increase the pressure within the can 10 until the pressure exceeds either the sealing capacity of cup 31 and/or the seal formed between cap 25 and disc 23. If desired a simple spring loadedvent valve (not shown) may be provided in chamber 33 to vent the chamber when the pressure therein exceeds the desired pressure within the can 10.

It will be readily observed that since only approximately 8 psi pressure is required within the can, the lid and pump combination may be very simply constructed from conventional materials. Furthermore, if desired, the disc 23, barrel 28 and cap 25 may be formed as a unitary monolithic construction. Likewise, collar 20 may be formed from any suitable semi-rigid material such as plastic, nylon or the like.

If desired, the cap 25, barrel 28 and disc 23 may be formed of molded plastic or the like. Furthermore, the need for a vent valve or other pressure limiting device may be eliminated by limiting the volume ratio of the barrel and cylinder. Due to the compressibility of air, the maximum pressure attainable is determined by this volume ratio. Accordingly, to obtain a maximum pressure of about 8 psi to about 14 psi, the volume of the barrel 28 displaced by piston 29 on the downward stroke should be about five to about eight times as large as the volume of the cavity 33 when the piston is in the maximum displacement position.

It will be readily observed that the lugs 22 depending from the collar 20 need not be of the precise geometric design illustrated but may be in the form of inclined indentures or slots in the manner of a conventional screw-type lid or the like. Other suitable arrangements for joining the cap with the collar will be readily apparent to those skilled in the art.

In accordance with the invention described, the can I 10 is enclosed and sealed by a top disc pressing a sealing material against the top of bead 12. Accordingly, the other components, such as the collar and retainer, need not form sealing contacts with the can. Therefore, collar 20 may fit loosely around the can so long as it is lodged beneath the bead l2.

For use with cans which do not contain a groove such as groove 12, alternate collar means may be used to attach the cap. For example, a metal or other resilient material in the form of a split ring may be used for the collar 20.

It will be readily observed that the cap assembly may be conveniently removed to extract balls from the can as desired. However, when play with the ball is finished, the ball may be replaced in the can, the cap 25 replaced and the can immediately repressurized.

Although the preferred embodiment of the invention contemplates a cap and pump assembly, it will be recognized that means other than the pump mechanism illustrated may be used in connection with the collar and cap of the invention. For example, the cap may include a valve or other inlet means adapted for connection with other convenient sources of compressed air such as a tire pump or compressed air tank.

While the invention has been described with particular reference to specific embodiments thereof, it will be understood that the forms of the invention shown and described in detail are to be taken as preferred embodiments of same, and that various changes and modifications may be resorted to without departing from the spirit and scope of the invention as defined by the appended claims.

What is claimed is:

1. Apparatus for enclosing and sealing the open end of a cylindrical container having an outwardly radially extending flange near the open end comprising a. collar means adapted to surround the outer surface of said container and having an internal dimension less than the external dimension of said flange,

b. cap means adapted to removeably mate with said collar means and form a seal with the top surface of said flange, and

c. means for injecting gas through said cap means into the interior of said container.

2. Apparatus as defined in claim 1 wherein said collar means comprises a semi-rigid circular body having a plurality of spaced downwardly projecting lugs, the bottom surfaces of which are inclined with respect to the major plane of said circular body; and said cap means includes inwardly projecting tabs adapted to mate with said lugs and urge said cap into sealing contact with said flange.

3. Apparatus as defined in claim 1 wherein said cap includes an upwardly projecting barrel with a reciprocal piston mounted therein and further includes a sealing plate enclosing the open end of said container and cooperating with said barrel and piston to define a cavity within said cap adjacent the end of said container, said sealing plate including a check valve permitting gas flow from said cavity into said container.

4. Apparatus as defined in claim 3 wherein the volume displaceable by said piston is about five to eight times as large as the volume of said cavity at maximum displacement of said piston.

5. Pressurization apparatus comprising:

a. a cylindrical container having an open end;

b. a groove encircling said container near said open end;

0. collar means adapted to fit within said groove;

d. elastic retainer means adapted to ride within vsaid groove and urge said collar means toward the open end of said container;

efsealing means adapted to mate with the open end of said container; 2

f. cap means enclosing said sealing means and adapted to be removeable affixed to said collar piston mounted within said barrel.

7. Apparatus as defined in claim 6 wherein said cap means, said sealing means and said barrel are formed in a single unitary construction defining a cavity adjacent the open end of said container.

8. Apparatus as defined in claim 7 wherein the volume of said piston reciprocating within said barrel reduces the volume of said cavity by a ratio of about 5 to 1 to about 8 to l. 

1. Apparatus for enclosing and sealing the open end of a cylindrical container having an outwardly radially extending flange near the open end comprising a. collar means adapted to surround the outer surface of said container and having an internal dimension less than the external dimension of said flange, b. cap means adapted to removeably mate with said collar means and form a seal with the top surface of said flange, and c. means for injecting gas through said cap means into the interior of said container.
 2. Apparatus as defined in claim 1 wherein said collar means comprises a semi-rigid circular body having a plurality of spaced downwardly projecting lugs, the bottom surfaces of which are inclined with respect to the major plane of said circular body; and said cap means includes inwardly projecting tabs adapted to mate with said lugs and urge said cap into sealing contact with said flange.
 3. Apparatus as defined in claim 1 wherein said cap includes an upwardly projecting barrel with a reciprocal piston mounted therein and further includes a sealing plate enclosing the open end of said container and cooperating with said barrel and piston to define a cavity within said cap adjacent the end of said container, said sealing plate including a check valve permitting gas flow from said cavity into said container.
 4. Apparatus as defined in claim 3 wherein the volume displaceable by said piston is about five to eight times as large as the volume of said cavity at maximum displacement of said piston.
 5. Pressurization apparatus comprising: a. a cylindrical container having an open end; b. a groove encircling said container near said open end; c. collar means adapted to fit within said groove; d. elastic retainer means adapted to ride within said groove and urge said collar means toward the open end of said container; e. sealing means adapted to mate with the open end of said container; f. cap means enclosing said sealing means and adapted to be removeable affixed to said collar means and urge said sealing means against the open end of said container, and cooperating with said sealing means to form an enclosed cavity; g. means for injecting gas into said cavity; and h. valve means permitting gas flow from said cavity into said container.
 6. Apparatus as defined in claim 5 wherein said means for injecting gas into said cavity comprises a barrel forming an extension of said cap and a reciprocal piston mounted within said barrel.
 7. ApParatus as defined in claim 6 wherein said cap means, said sealing means and said barrel are formed in a single unitary construction defining a cavity adjacent the open end of said container.
 8. Apparatus as defined in claim 7 wherein the volume of said piston reciprocating within said barrel reduces the volume of said cavity by a ratio of about 5 to 1 to about 8 to
 1. 